An input video signal is applied to a transmission line first through a time direction emphasizer for emphasizing the levels of time direction high frequency components of the video signal, relative to the levels of low frequency components thereof; secondary through a vertical direction emphasizer; and thirdly through a horizontal direction emphasizer. Further, the received video signal is outputted as an output video signal from the transmission line first through a horizontal direction deemphasizer for deemphasizing the levels of horizontal direction high frequency components of the video signal, relative to the levels of low frequency components thereof; secondary through a vertical direction deemphasizer; and thirdly through a time direction deemphasizer. The emphasis and deemphasis method enables the dynamic range of the transmission line to be utilized effectively, while preventing erroneous operation on the reception side.